title: Cis-2-dodecenoic acid quorum sensing system modulates N-acyl homoserine lactone production through RpfR and cyclic di-GMP turnover in Burkholderia cenocepacia.
abstract: BACKGROUND
  Burkholderia cenocepacia employs both N-Acyl homoserine lactone (AHL) and cis-2-dodecenoic acid (BDSF) quorum sensing (QS) systems in regulation of bacterial virulence. It was shown recently that disruption of BDSF synthase RpfFBc caused a reduction of AHL signal production in B. cenocepacia. However, how BDSF system influences AHL system is still not clear.
  
  
  RESULTS
  We show here that BDSF system controls AHL system through a novel signaling mechanism. Null mutation of either the BDSF synthase, RpfFBc, or the BDSF receptor, RpfR, caused a substantial down-regulation of AHL signal production in B. cenocepacia strain H111. Genetic and biochemical analyses showed that BDSF system controls AHL signal production through the transcriptional regulation of the AHL synthase gene cepI by modulating the intracellular level of second messenger cyclic di-GMP (c-di-GMP). Furthermore, we show that BDSF and AHL systems have a cumulative role in the regulation of various biological functions, including swarming motility, biofilm formation and virulence factor production, and exogenous addition of either BDSF or AHL signal molecules could only partially rescue the changed phenotypes of the double deletion mutant defective in BDSF and AHL signal production.
  
  
  CONCLUSIONS
  These results, together with our previous findings, thus depict a molecular mechanism with which BDSF regulates AHL signal production and bacterial virulence through modulating the phosphodiesterase activity of its receptor RpfR to influence the intracellular level of c-di-GMP.
authors.affiliation: Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos 138673, Singapore.
authors.forename: Yinyue
authors.initials: Y
authors.lastname: Deng
authors.forename: Amy
authors.initials: A
authors.lastname: Lim
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Tielin
authors.initials: T
authors.lastname: Zhou
authors.forename: Shaohua
authors.initials: S
authors.lastname: Chen
authors.forename: Jasmine
authors.initials: J
authors.lastname: Lee
authors.forename: Yi-Hu
authors.initials: YH
authors.lastname: Dong
authors.forename: Lian-Hui
authors.initials: LH
authors.lastname: Zhang
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D057508:Burkholderia cenocepacia / Q000235:genetics / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism*; D015536:Down-Regulation; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D053038:Quorum Sensing; D015398:Signal Transduction
chemical_list: C527562:2-dodecenoic acid; D001426:Bacterial Proteins; D005229:Fatty Acids, Monounsaturated; C088386:homoserine lactone; D006152:Cyclic GMP; D015107:4-Butyrolactone